Extruder for three-dimensional additive printer

ABSTRACT

An extruder for a three-dimensional additive printer can be used to receive and dispense material. The extruder can include a number of different components including a nozzle with an adjustable opening configured to discharge material. The nozzle can be configured to be moved and rotated so as to align the adjustable opening with a plurality of paths along which the material is configured to be deposited for generating a three-dimensional object. The adjustable opening can comprise a first orifice and an obstruction member configured to move with respect to the first orifice. The position of the obstruction member can adjust the size of the opening area of the adjustable opening.

BACKGROUND

Technical Field

Certain embodiments disclosed herein relate generally tothree-dimensional (3D) printing systems. In particular, extrusion headsand methods related to extrusion with the 3D printing systems arediscussed.

Description of the Related Art

Three-dimensional (3D) printing, also known as additive manufacturing,includes a number of different types of processes where successivelayers of material are built up to create a three-dimensional object.Some types of additive manufacturing processes involve extruding aheated material from a nozzle. Despite recent advances in 3D printing,most commercially available 3D printers are slow and inefficient.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should in no way be interpreted as limitingthe scope of the inventions.

FIG. 1 shows a schematic of a 3D printing system.

FIG. 2 shows various nozzle orifices that can be used with 3D printingsystems.

FIG. 3A illustrates a flow path of an extruder for depositing material.

FIG. 3 shows a nozzle with parts of a rotation control.

FIGS. 4 and 4A show a nozzle with adjustable opening in a firstposition.

FIGS. 5 and 5A show the nozzle with adjustable opening in a secondposition.

FIG. 6 illustrates another nozzle with adjustable opening.

FIGS. 6A and B show various positions of the nozzle with adjustableopening of FIG. 6.

FIGS. 7A-B show another nozzle with adjustable opening.

FIGS. 8A-E illustrate various orifice shapes.

FIG. 9A-9C illustrate additional orifice designs.

FIG. 10 is a dual nozzle.

FIG. 11 is a dual nozzle, with each nozzle having an adjustable opening.

DETAILED DESCRIPTION

While certain embodiments are described, these embodiments are presentedby way of example only, and are not intended to limit the scope ofprotection. Indeed, the novel methods and systems described herein maybe embodied in a variety of other forms. Furthermore, various omissions,substitutions, and changes in the form of the methods and systemsdescribed herein may be made without departing from the scope ofprotection.

Three-dimensional (3D) printers create 3D objects by using additiveprocesses during which an object is created by laying down successivelayers of material. Each of these layers can be seen as a thinly slicedhorizontal cross-section of the final object.

3D printers range from very expensive and complex systems to theextremely simple. Thus, they are used by the casual hobbyist, as well asprofessionals. Many available 3D printers utilize extruders that inoperation resemble hot glue guns. For example, a stepper motor pushesthermoplastic material into a hot head with a resistive heater andthermistor feedback. The extruder head temperature and speed of materialare balanced to get acceptable lines of printing. For fine printing asmaller nozzle can be used. But this also requires more passes to fillin the printed structure. Thus, the size of the orifice in the nozzlecan be a large factor in the time required to build the object, as wellas being a factor in the level of detail possible. Generally speaking,the larger the orifice the faster the build time and the lower the levelof possible detail.

In some embodiments, an improved 3D printer system has amulti-directional, rotatable extruder. The extruder can be controlled bya computer controller implementing a computer generated model (forexample, represented in G-code). During operation, the extruder can becontrolled to trace a path along which the material is deposited. Insome embodiments, the extruder can have a non-circular orifice that canbe controlled to reduce the number of passes needed to generate a 3Dobject. In some embodiments, the extruder additionally or alternativelyincludes a variable-size opening configured to deposit a controlled beadof material in order to reduce the number of passes needed to generate a3D object.

FIG. 1 illustrates a 3D printing system 100A according to someembodiments of the invention. A 3D printing system 100A can include amaterial feeder 112, a motor 126, a controller 130 and an extruder 120A.The material feeder 112 with input from the controller 130 can controlthe feed rate of material 110 to the extruder 120A.

The extruder 120A can include a heater 122 and a nozzle 124A. Theextruder can deposit material 110 received from the material feeder 112along a flow path controlled by the motor 126 to create a 3D object 140.

Material feeder 112 can be a stepper motor or any other suitableactuator. Material 110 is preferably contained in a spool, but can alsobe in other forms, such as sticks, beads, and liquid form. Thus, thematerial feeder 112 can push or pull material 110 from the spool, butmay also control flow in this same or in other ways from a materialhopper and/or channel through which the material 110 can flow.

Material 110 can be thermoplastic, metal wire, ceramic, chocolate, andthe like depending on the application. Material 110 can be fed by thematerial feeder to an extruder 120A.

The extruder 120A includes a heater 122 and a nozzle 124A. The tip ofthe nozzle 124 includes an orifice from which the material 110 isdeposited. In particular, molten material heated by the heater 122 isforced out of the nozzle orifice and deposited on the 3D object 140,which can be generated layer by layer.

The nozzle 124A is moved in three dimensions by one or more motors 126.Nozzle 124A can be moved in layers, moving in two dimensions to depositone horizontal slice or plane at a time, before moving upwards to begina new slice. The speed of the nozzle 124A, as well as the flow ofmaterial 110 can be controlled to form a smooth, consistent plane.

In some embodiments, the 3D printing system 100A includes a rotationcontrol 128 configured to rotate the nozzle 124A. A rotation control 128can be used with a number of nozzle styles; it is particularly desirablewhere the orifice of the nozzle is a non-circular or a non-single pointorifice, such as an elongated orifice. The rotation control 128 canrotate a nozzle 124A with an elongated orifice such as orifices 220, 230shown in FIG. 2. It this way the position of the orifice can becontrolled as the extruder travels along a flow path as shown in FIG.3A.

FIG. 2 illustrates extruder orifices according to some embodiments ofthe invention. In 210, an orifice of a typical extruder nozzle isillustrated. As can be seen, small amounts of the material can bedeposited from the narrow orifice 210. Improved orifices are illustratedat 220 and 230, which can correspond to the opening of the extruder120A. Because these openings are wider than the opening 210, morematerial can be deposited. The orifice 230 is offset from the center. Insome embodiments, alternative openings can be used, such as an openingpositioned in the diagonal direction.

FIG. 3A illustrates a flow path 306 of an extruder for depositingmaterial. Illustrated path 306 is a desired flow path that needs to betraced by the extruder 120A. The material is deposited along area 304,which represents part of an object, such as the object 140. As can beseen, the area 304 is wider than the nozzle opening 210 illustrated inFIG. 2. It will be understood that orifice 210 would require multiplepasses in order to fill in the area 304. In contrast, a wider nozzleorifice 302 can deposit material along the entire area 304 in a singlepass. The wider nozzle orifice 302 can correspond to the orifice 220 or230 illustrated in FIG. 2. As is illustrated in FIG. 3A, the path 306 iscurved. The nozzle 124A can be rotated in order to trace the path anddeposit the material accurately and efficiently.

In some embodiments, the tip of the nozzle 124A is rotated so as tocontrol the deposition of the material 110 with a rotation control 128.As illustrated in FIG. 1, all or part of the rotation control 128 can bepart of the extruder 120A. Rotation control 128 can include a motorconnected to a belt, gear drive, or the like for rotating the nozzle124A. The gear or wheel of a belt drive portion of the rotation control128 is shown in FIG. 3. Also shown is a position control 132 in the formof rotary encoder marks which can be used with a vision system (notshown) and the controller 130 to accurately control the rotationalposition of the orifice. It will be understood that the position control132 can take any number of forms. For example, the disk 125 can includea position control 132 in the form of a detent and a switch to mark theinitial position. The disk 125 can be connected to a stepper motor tocontrol the rotational position of the orifice as it moves from theinitial position.

The entire nozzle 124A may rotate, or only the bottom portion. Forexample, a rotatable disk 125 with the orifice 220 or 230 can bepositioned at the base of the extruder 124A.

An extruder with rotation control can work as follows, referring back toFIG. 1. Controller 130 controls the materials feeder 112 and theextruder 120A. For example, the controller 130 controls the rate withwhich the material feeder 112 feeds the material 110 into the extruder.Thus, where the material 110 is on a spool, the controller 130 andmaterial feeder 112 can control the rate at which the spool rotates. Thecontroller 130 can also control the heat of the heater 122. The heater122 can be a metal block resistance heater, laser heater, or other typeof heater. Thus, the material 110 can melt as it passes through theheated metal block. The controller 130 can further control the motor 126of the extruder and the rotation control 128 to move the nozzle 124A todeposit the material 110 along a plurality of paths. Controller 130,which can be a general purpose or special purpose controller, can beconnected to memory (not shown) for storing various parametersconfigured to operate the system 100A. Such parameters can include acomputer model for generating the 3D object 140.

In some embodiments, as shown in FIG. 1, a 3D printing system 100A canhave a nozzle 124A with a variable-size orifice and a nozzle openingcontrol 129. The nozzle opening control 129 can be in addition to, partor, or instead of the rotation control 128. In one embodiment, the sizeof the orifice (such as the width) of the nozzle 124A is varied tocontrol the deposition of the material 110. For example, the nozzleorifice can be a non-circular opening. As another example, the openingcan be of any suitable shape or combination of shapes. Illustratedextruder 120A includes nozzle opening control 129 configured to controlthe size of the opening at the orifice. In one embodiment, nozzleopening control 129 is an actuator configured to vary the size of thetip. Nozzle opening control 129 can be under control of the controller130.

As will be discussed in more detail below, an extruder for athree-dimensional additive printer can be used to receive and dispensematerial. The extruder can be part of the 3D printer, but can also besold as a standalone part. The extruder can include a number ofdifferent components including a nozzle. The nozzle can have anadjustable opening configured to discharge material, the adjustableopening defining an opening area through which material can flow. Thenozzle can be configured to be moved and rotated so as to align theadjustable opening with a plurality of paths along which the material isconfigured to be deposited for generating a three-dimensional object.The adjustable opening can comprise a first orifice, an obstructionmember configured to move with respect to the first orifice, and arotating disk. The rotating disk can be configured to rotate withrespect to the first orifice to control the position of the obstructionmember so as to define two or more positions of the obstruction memberto adjust the size of the opening area of the adjustable opening.

Additional details of the controller 130 and control system forcontrolling the rotation control and the nozzle opening control aredisclosed in U.S. Patent Appl. No. 62/271,144 filed Dec. 22, 2015 titled“Rotation and Nozzle Opening Control of Extruders in Printing”, thedisclosure of which is hereby incorporated by reference in its entirety.

What follows are various embodiments of and/or portions of extruders120A, including all or portions of nozzles, orifices, rotation controlsand nozzle opening controls. It will be understood that these componentscan be part of the previously described embodiments of extruders 120Aand/or 3D printers 110A.

Turning now to FIGS. 4-5A, an embodiment of nozzle 124B is illustratedwith a variable-size opening 2. In particular, the nozzle 124B includesa slide 4 positioned at the orifice 6 to control the size of the opening2. FIGS. 4 and 4A show the nozzle with adjustable opening in a firstposition, and FIGS. 5 and 5A show the nozzle with adjustable opening ina second position.

An extruder 120A for a three-dimensional additive printer can include anozzle 124B. The extruder can be configured to receive and dispensematerial 110. The nozzle 124B can include an adjustable opening 2configured to discharge the material 110. The adjustable opening 2 candefine an opening area through which material can flow. The nozzle canalso include an orifice 6 and an obstruction member 4 configured to movewith respect to the orifice 6.

In the illustrated embodiment, the obstruction member 4 is a slidepositioned adjacent the orifice 6. The slide can be in a slot 12. Theslide 4 is configured to move (linearly in the illustrated embodiment)with respect to the orifice 6 to thereby control the size of the openingarea 2. The opening area is the portion of the orifice 6 that isunimpeded by the slide 4. It will be understood that the obstructionmember 4 can be any structure configured to block a portion of theorifice 6 to thereby vary the opening area 2 and the amount of materialthat can flow through the orifice.

In the illustrated embodiment, the nozzle 124B has a nozzle body 8 witha channel 10 that extends therethough. The channel 10 ends at theorifice 6. Material 110 can flow through the channel 10. In someembodiments, the nozzle body 8 can be metal and can be part of aresistance heater 122 to melt the material 110 as it passes through thechannel 10. For example, the material 110 can be a plastic filamentcontained on a spool that is feed into the extruder and thereby into thenozzle 124B. The resistance heater 122 can heat the filament sufficientfor the nozzle body and/or obstruction member 4 to modify the amount ofmaterial that flows out of the orifice. The filament is also heatedsufficient for it to fuse to material that has already been laid down tocreate the 3D object 140.

As the nozzle 124B has an adjustable opening 2, it can be desirable forthe nozzle to be moved and rotated so as to align the adjustable openingwith a desired path along which the material is to be deposited forgenerating a three-dimensional object. Thus, the nozzle 124B can includerotation controls 128 and can be further controlled by one or moremotors 126. The one or more motors 126 can control the position of thenozzle 124B generally while the rotation controls 128 can control theangular position of the opening 2. Thus, in some embodiments, the motors126 comprise three motors, such as three servo or stepper motors. Two ofthe motors can control the position of the nozzle along X and Ycoordinates in a Cartesian coordinate system, while the third motor cancontrol the height of the nozzle along Z coordinates. Other coordinatesystems and motor configurations can also be used.

The nozzle 124B can also include nozzle opening controls 129. The nozzleopening controls 129 can control the size of the opening area 2. Forexample, the opening area 2 can be set at a beginning or end of aparticular deposition path and/or layer. It can also be done in realtime as the nozzle moves along a deposition path. In one embodiment, a3D printing system designed for a home hobbyist can be configured toonly change the opening area 2 at the beginning or end of a particulardeposition path and/or layer. In contrast a more complex and expensive3D printing system for an industrial user can be configured to adjustthe opening area 2 in real time as the nozzle moves along a depositionpath.

As illustrated, the nozzle opening controls 129 can include a slide 4.The slide 4 can be positioned in a slot 12 formed in the nozzle body 8.The slide 4 can be positioned inside and/or outside of the nozzle body8. The nozzle can include a keyway or rail system 14 to providestability as the slide 4 moves with relation to the orifice 6. Forexample, the nozzle body can have a keyway and the slide can have aprotrusion positioned in the keyway, which keyway and protrusion arerepresented schematically at 14. To increase stability, the keyway maybe positioned in a rail that extends past and outside of the nozzle bodyas is shown.

The position of the obstruction member 4, here a slide, can becontrolled in one of many ways by the nozzle opening controls 129. Forexample, a motor and gear system employing a rack and pinon and canused. In the illustrated embodiment, the nozzle 124B includes a rotatingdisk 20 configured to rotate with respect to the orifice 6 to controlthe position of the obstruction member 4 so as to adjust the size of theopening area of the adjustable opening 2. The rotating disk 20 can bestbe understood referring to both FIGS. 4 and 5, and FIGS. 4A and 5A.Reviewing these figures it can be seen that a pin 16 is positionedwithin a channel or slot 18 in the rotating disk 20. As the diskrotates, the pin moves within the channel which causes the slide to movein or out. The disk itself can be controlled by a gear and/or beltsystem connected to one or more motors. For example, as will bedescribed in more detail below, the disk 20 can include a plurality ofgear teeth. The disk can also provide a channel to receive a beltsimilar to that shown in FIG. 3.

Comparing FIGS. 4-4A with 5-5A it can be seen how when the disk 20rotates the slide 4 moves linearly with respect to the orifice to changethe size of the opening 2. The obstruction member 4, here a slide, canhave a plurality of positions. For example, the obstruction member canmove between a fully open and a fully closed position. In the fully openposition, the obstruction member may not block any of the orifice 6. Inthe fully closed position, the obstruction member can block the orificecompletely. In some embodiments the obstruction member may not have afully blocking position. The obstruction member in a first position candefine a minimum opening area and the obstruction member in a secondposition can define a maximum opening area. In the second position theobstruction member may or may not be blocking the orifice 6. As shown inFIG. 4, the obstruction member is not blocking the orifice so that themaximum opening area equal to and defined by the size of the orifice 6.It will be understood that an obstruction member 4 that blocks theorifice can beneficially prevent heated material from dripping onto a 3Dprinted object or work area. Further, the obstruction member whenblocking material flow can beneficially reduce the need for adjustmentsby the material feeder to retract the material from the extruder atcertain times during the 3D printing process.

Preferably, an axis of rotation of the rotating disk is aligned with anaxis of rotation of the nozzle. In some embodiments, the axis ofrotation of the rotating disk will be centered on the orifice, while theaxis of rotation of the nozzle will be centered at an edge of theorifice, or some other portion of the orifice, such as the center of theminimum opening area. The rotating disk 12 and the opening 2 can beconfigured to rotate both together and separately.

In some embodiments, an extruder for a three-dimensional additiveprinter can be provided. The extruder can be configured to receive anddispense material and can comprise a nozzle with an adjustable openingconfigured to discharge material. The adjustable opening can define anopening area through which material can flow, the nozzle configured tobe moved and further configured to be rotated so as to align theadjustable opening with a plurality of paths along which the material isto be deposited for generating a three-dimensional object. Theadjustable opening can include an orifice through which material canflow, a slide adjacent the first orifice, and a rotating disk configuredto rotate with respect to the orifice. The slide can be configured tomove linearly with respect to the orifice to selectively obstruct andallow material flow out of the orifice. The rotating disk can controlthe position of the slide. The rotating disk preferably coupled to theslide such that rotation of the rotating disk causes linear movement ofthe slide so as to define two or more positions of the slide to adjustthe size of the opening area of the adjustable opening.

According to some embodiments, a first position of the slide completelyblocks the orifice to prevent material flow. The orifice can have alength and a width that are not equal.

In some embodiments, the extruder can further comprise a pin on theslide and a slot in the rotating disk. The pin can be positioned withinthe slot such that rotation of the rotating disk causes linear (oranother type of) movement of the pin and the slide. The slot can be aspiral shaped slot, such as a logarithmic spiral. To increase stabilityof the slide, a rail system with a keyway and a protrusion within thekeyway can be included. The slide can move within the rail system.

The extruder can be part of a three-dimensional additive printer with aheater configured to heat the material to be discharged by the nozzleand a material feeder configured to vary flow of material to theextruder. The system can further comprise at least one of a belt driveand a gear drive to control the rotation of the rotating disk. As willbe described in more detail below, the three-dimensional additiveprinter can further include a second nozzle with a second orificethrough which material can flow separate from the first orifice. The twonozzles can be part of the same extruder, or separate extruders.

Looking now to FIG. 6, another nozzle 124C with adjustable opening 2will be described. The nozzle 124C is similar to the nozzle 124Bdescribed above with a different type of obstruction member 4. Here theobstruction member 4 is part of the rotating disk 20. As the disk 20rotates, the obstruction member 4 moves with respect to the orifice 6 toblock and/or open the orifice 6, thereby defining the opening areathrough which material can flow. The rotating disk 20 can include anorifice 22. Looking at FIG. 6A, various positions of the rotating disk20 and obstruction member 4 are shown illustrating the relativepositions of the orifice 6 and the second orifice 22. FIG. 6B moreclearly illustrates one position of the rotating disk 20 and obstructionmember 4 with respect to the orifice 6. The overlap between the twoorifices can define the opening area 2. The portions of the orifice 6are shown covered by the obstruction member 4 (represented by shading)to indicate the area of blocked flow.

It will be understood that the rotating disk can be one of many shapes.For example, the disk is illustrated in FIG. 6 as being circular, but itis not restricted to this shape. In some embodiments, the disk can beother shapes such as semi-circular, triangular, etc. FIG. 7A-Billustrates an alternative embodiment 124D where the obstruction member4 is semi-circular. As can be seen, the obstruction member 4 does nothave an orifice, but merely rotates with respect to the orifice 6 toblock (FIG. 7A) and/or allow (FIG. 7B) flow. Still further, the disk canbe multiple disks. For example, the adjustable opening can be formedlike an iris with a plurality of disks that move in and out of theopening.

It will also be understood that the orifice 22 on the obstruction membercan be any number of shapes. FIGS. 8A-E illustrate various shapes oforifice 22. For example, the orifice 22 can be triangular (FIG. 8C) oroval (FIG. 8D). The orifice can also be based on an Archimedean spiral(FIG. 8B) or a logarithmic spiral (FIG. 8E). The orifice can based on aspiral can be formed by any portion of the spiral. The spiral can defineone or more boundary of the orifice.

Looking now to FIGS. 9A-9C, additional embodiments of obstructionmembers 4 are shown. It will be understood that the obstruction member 4can include one or more orifice 22. The one or more orifices can be thesame or different shapes. The one or more orifices can also be alignedalong different positions along an axis of rotation.

For example, in FIG. 9A, the disk 20 includes six orifices 22. Each ofthe illustrated orifices 22 are a different size, yet based on the samesized circle. The diameter of the circle defines the width of eachorifice, and for all but the actual circle the length is greater thanthe width. Thus, for all but the actual circle the shape of the orificeis a rectangle capped by two half-circles, each on an opposing end ofthe rectangle. (This can be considered a type of rectangle with roundedcorners.) An outer edge of each orifice is aligned with a circle 24centered on the axis of rotation of the disk 20. It will be understoodthat the orifices 22 can be aligned in different manners, such as beingcentered with a circle 26 centered on the axis of rotation of the disk,or aligned at an inner 28 or outer 24 edge of a circle centered on theaxis of rotation of the disk as is illustrated in FIG. 9B. FIG. 9C showsorifices of various shapes and sizes aligned at different positions onthe disk 20.

In some embodiments, where there are more than one orifice, at leastsome of the orifices can be non-circular orifices. It will be understoodthat the first orifice 6 on the nozzle body could also be any number ofshapes, including those described with reference to the orifice 22. Insome embodiments, the first orifice is rectangular with rounded cornersand the second orifice is one of Archimedean spiral, logarithmic spiral,and triangular. In some embodiments, the rotating disk comprises a thirdorifice being smaller than the second orifice. The second orifice candefine a maximum flow area of the adjustable opening and the thirdorifice can define a minimum flow area of the adjustable opening.

According to some embodiments, an extruder for a three-dimensionaladditive printer is configured to receive and dispense material. Theextruder can comprise a nozzle with an adjustable opening configured todischarge material. The adjustable opening defining an opening areathrough which material can flow, the nozzle configured to be moved andfurther configured to be rotated so as to align the adjustable openingwith a plurality of paths along which the material is configured to bedeposited for generating a three-dimensional object. The adjustableopening can comprise a first orifice through which material can flow,and a rotating disk.

The rotating disk can be configured to rotate along an axis of rotationwith respect to the first orifice. The rotating disk can define anobstruction member and a second orifice, the rotating disk configured toselectively align the second orifice and obstruction member with thefirst orifice to allow or prevent the flow of material from the firstorifice so as to define two or more positions to adjust the size of theopening area of the adjustable opening.

In a first position, the rotating disk can completely block the firstorifice with the obstruction member to prevent material flow. In asecond position, the rotating disk can align the first and secondorifices such that the first orifice is unobstructed by the obstructionmember. The rotating disk can have a number of positions between thefirst and second position to adjust the size of the opening as desired.

The extruder can also be part of a three-dimensional additive printer asdiscussed above.

From all of the above discussions, it will be understood that anextruder for a three-dimensional additive printer can be used to receiveand dispense material. It can be part of the 3D printer, but can also besold as a standalone part. The extruder can include a number ofdifferent components including a nozzle. The nozzle can have anadjustable opening configured to discharge material, the adjustableopening defining an opening area through which material can flow. Thenozzle can be configured to be moved and rotated so as to align theadjustable opening with a plurality of paths along which the material isconfigured to be deposited for generating a three-dimensional object.The adjustable opening can comprise a first orifice, an obstructionmember configured to move with respect to the first orifice, and arotating disk. The rotating disk can be configured to rotate withrespect to the first orifice to control the position of the obstructionmember so as to define two or more positions of the obstruction memberto adjust the size of the opening area of the adjustable opening.

The extruder can also include a heater to receive material from amaterial feeder. The nozzle body itself may form part of the heater,such as where the nozzle is a metal block and the heater is a resistanceheater the flows electricity to the metal block.

The obstruction member can take many forms. For example, the obstructionmember can be a slide or part of the disk designed to move with respectto the first orifice to block and/or allow material flow out of thefirst orifice. In some embodiments, the rotating disk comprises theobstruction member and a second orifice, the size of the opening area ofthe adjustable opening determined by the amount of overlap between thefirst orifice and the second orifice. The disk can include a thirdorifice. In some embodiments, the obstruction member comprises a slidepositioned slot adjacent the first orifice, the slide can be configuredto move with respect to the first orifice to thereby control the size ofthe opening area.

It will be understood that the obstruction member, whether a slide ordisk can be swappable. For example, a multiple slides can be provided,each with different opening widths, the length being adjustable aspreviously described. Similarly, multiple obstruction member disks 4, 20can be provided with orifices 22 of different sizes and/or shapes. Afirst obstruction member disk 4, 20 can removed and replaced with adifferent obstruction member disk 4, 20 having a different orificedesign.

Turning now to FIGS. 10 and 11, two additional embodiments of extruderare shown. In each of these embodiments the extruder includes twonozzles. As can be seen in FIG. 10, one nozzle is identical to thenozzle 124B described above with respect to FIGS. 4-5B. The other nozzle124E has a fixed or non-adjustable orifice 30. FIG. 11 also shows twonozzles. The first nozzle is identical to the nozzle 124B describedabove and the second nozzle 124F is substantially the same, but with alarger orifice 32.

The two nozzles of the various embodiments can use the samematerial/same type of material, but can also use different materials ortypes of materials. One nozzle can be used for speed and the othernozzle can be used for fine detail work. Dual nozzle extruders can alsobe used with different colors, and/or a structural material and asupport material. The two nozzles can be coupled together so as to movetogether, such as along the X, Y, and Z axes. But, at least one of thenozzles can be configured to rotate, such as around the axis separatefrom the other nozzle. So, for example, with reference to FIG. 10, thenozzle 124B can rotate around the Z-axis (which extends out of page)while the nozzle 124E does not rotate. At the same time, the two nozzlesmove together along the X and Y axes, as well as moving together whenraised or lowered along the Z axis. In the embodiment of FIG. 11, bothnozzles can rotate about the Z-axis independently, while moving togetherin a along the X and Y axis and up and down along the Z axis. Thus, theorifices of the nozzles can be aligned along a single plane and stayaligned even as they move and rotate.

According to some embodiments, a three-dimensional additive printer cancomprise a first extruder and a second extruder both configured toreceive and dispense material, and a control system. The first extrudercan include a first nozzle comprising a first orifice configured todischarge material. The second extruder can include a second nozzlecomprising a second orifice configured to discharge material, the secondorifice having a different size or shape than the first orifice. Thethree-dimensional additive printer can be configured to alternativelyprint from either the first extruder or the second extruder. The controlsystem can comprise at least one motor, the control system configured toprovide positional control of the first and second extruders within acoordinate system. The first and second extruders configured to movetogether within the coordinate system when printing, and the controlsystem further configured to selectively rotate the first orifice whenprinting, separate from the second orifice.

The first and second orifices can be aligned along a single plane. Thefirst orifice can be circular or non-circular, as can the secondorifice. In some embodiments, the first orifice is rectangular withrounded corners and the second orifice is circular. The 3D printer canalso include an obstruction member moveable with respect to the firstorifice to control a size of the first orifice. A material feeder andone or more heaters can also be included as has been describedpreviously.

According to some embodiments, a three-dimensional additive printer cancomprise a material feeder configured to vary flow of material to beprinted as a three-dimensional object; a first extruder configured toreceive material from the material feeder; a second extruder configuredto receive material from the material feeder, the three-dimensionaladditive printer configured to alternatively print from either the firstextruder or the second extruder; and a control system. The firstextruder can comprise a first heater configured to heat materialreceived from the material feeder, and a first nozzle comprising a firstorifice configured to discharge the heated material. The second extrudercan comprise a second heater configured to heat material received fromthe material feeder; and a second nozzle comprising a second orificeconfigured to discharge the heated material, the second orifice beingsmaller than the first orifice. The control system can include at leastone motor, the control system configured to provide Cartesian control ofthe first and second extruders along X, Y, and Z axes, the first andsecond extruders configured to move together along the X, Y, and Z axeswhen printing, and further configured to selectively rotate the firstorifice around the Z axis when printing.

In some embodiments, Z axis rotation of the first extruder does notrotate the second extruder. As has been discussed, the first and secondorifices can be aligned along a single plane.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. In addition, while a number of variations of the invention havebeen shown and described in detail, other modifications, which arewithin the scope of this invention, will be readily apparent to those ofskill in the art based upon this disclosure. It is also contemplatedthat various combinations or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the invention. Accordingly, it should be understood thatvarious features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the disclosed invention. Thus, it is intended that the scope ofthe present invention herein disclosed should not be limited by theparticular disclosed embodiments described above, but should bedetermined only by a fair reading of the claims that follow.

Similarly, this method of disclosure, is not to be interpreted asreflecting an intention that any claim require more features than areexpressly recited in that claim. Rather, as the following claimsreflect, inventive aspects lie in a combination of fewer than allfeatures of any single foregoing disclosed embodiment. Thus, the claimsfollowing the Detailed Description are hereby expressly incorporatedinto this Detailed Description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. An extruder for a three-dimensional additive printer, the extruder configured to receive and dispense material comprising: a nozzle comprising an adjustable opening configured to discharge material, the adjustable opening defining an opening area through which material can flow, the nozzle configured to be moved and further configured to be rotated so as to align the adjustable opening with a plurality of paths along which the material is configured to be deposited for generating a three-dimensional object, the adjustable opening comprising: a first orifice; an obstruction member configured to move with respect to the first orifice, the obstruction member comprising a slide positioned adjacent the first orifice, the slide configured to move linearly with respect to the first orifice to thereby control a size of the opening area; and a rotating disk configured to rotate with respect to the first orifice to control a position of the obstruction member so as to define two or more positions of the obstruction member to adjust the size of the opening area of the adjustable opening; and a pin on the slide and a slot in the rotating disk, the pin positioned within the slot such that rotation of the rotating disk causes linear movement of the pin and the slide, wherein the slot has a spiral shape such that rotation of the rotating disk causes the pin to move along the spiral shape.
 2. The extruder of claim 1, wherein a first position of the two or more positions of the obstruction member completely blocks the first orifice to prevent material flow.
 3. The extruder of claim 1, wherein the rotating disk comprises the obstruction member and a second orifice, the size of the opening area of the adjustable opening determined by an amount of overlap between the first orifice and the second orifice.
 4. The extruder of claim 3, wherein the first and second orifices are non-circular orifices.
 5. The extruder of claim 4, wherein the first orifice is rectangular with rounded corners and the second orifice is one of Archimedean spiral, logarithmic spiral, or triangular.
 6. The extruder of claim 3, wherein the rotating disk further comprises a third orifice, the third orifice being smaller than the second orifice.
 7. The extruder of claim 6, wherein the second orifice defines a maximum size of the opening area of the adjustable opening and the third orifice defines a minimum size of the opening area of the adjustable opening.
 8. The extruder of claim 6, wherein the second and third orifices are positioned on the rotating disk such that a circle passing through the center of both the second and third orifices has an axis aligned with an axis of rotation of the rotating disk.
 9. The extruder of claim 1, wherein the first orifice is a non-circular orifice.
 10. The extruder of claim 1, wherein the first orifice has a length and a width that are not equal.
 11. The extruder of claim 1, wherein the first orifice comprises a shape that is at least one of rectangular, elliptical, triangular, Archimedean spiral, or logarithmic spiral.
 12. The extruder of claim 1, wherein the nozzle further comprises a keyway, the slide having a protrusion in the keyway to provide stability as the slide moves with relation to the first orifice.
 13. The extruder of claim 12, wherein the protrusion moves within the keyway as the slide moves with relation to the first orifice.
 14. The extruder of claim 1, wherein an axis of rotation of the rotating disk is aligned with an axis of rotation of the nozzle.
 15. The extruder of claim 1, wherein the rotating disk and the first orifice are configured to rotate both together and separately.
 16. The extruder of claim 1, wherein the first orifice has a rectangular shape, and wherein the slide is configured move linearly along a planar surface of the rectangular shape.
 17. A three-dimensional additive printer comprising: the extruder of claim 1 further comprising a heater configured to heat the material to be discharged by the nozzle; and a material feeder configured to vary flow of material to the extruder.
 18. The three-dimensional additive printer of claim 17, further comprising at least one of a belt drive or a gear drive to control the rotation of the rotating disk.
 19. An extruder for a three-dimensional additive printer, the extruder configured to receive and dispense material comprising: a nozzle comprising an adjustable opening configured to discharge material, the adjustable opening defining an opening area through which material can flow, the nozzle configured to be moved and further configured to be rotated so as to align the adjustable opening with a plurality of paths along which the material is configured to be deposited for generating a three-dimensional object, the adjustable opening comprising: a first orifice through which material can flow; a slide positioned adjacent the first orifice, the slide configured to move with respect to the first orifice to selectively obstruct and allow material flow out of the first orifice; a rotating disk configured to rotate with respect to the first orifice to control a position of the slide, the rotating disk coupled to the slide such that rotation of the rotating disk causes movement of the slide so as to define two or more positions of the slide to adjust a size of the opening area of the adjustable opening; and a pin on the slide and a slot in the rotating disk, the pin positioned within the slot such that rotation of the rotating disk causes linear movement of the pin and the slide, wherein the slot has a spiral shape such that rotation of the rotating disk causes the pin to move along the spiral shape.
 20. The extruder of claim 19, wherein a first position of the slide completely blocks the first orifice to prevent material flow.
 21. The extruder of claim 19, wherein the first orifice has a length and a width that are not equal.
 22. The extruder of claim 19, wherein the nozzle further comprises a keyway, the slide having a protrusion in the keyway to provide stability as the slide moves with relation to the first orifice.
 23. The extruder of claim 19, wherein the first orifice has a rectangular shape, and wherein the slide is configured move linearly along a planar surface of the rectangular shape.
 24. A three-dimensional additive printer comprising: the extruder of claim 19 further comprising a heater configured to heat the material to be discharged by the nozzle; and a material feeder configured to vary flow of material to the extruder.
 25. The three-dimensional additive printer of claim 24, further comprising at least one of a belt drive or a gear drive to control the rotation of the rotating disk.
 26. The three-dimensional additive printer of claim 24, further comprising a second nozzle with a second orifice through which material can flow separate from the first orifice. 